• Title/Summary/Keyword: web reinforcement

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Relative Feedback with Reinforcement Learning (강화학습을 사용한 연관성 피드백)

  • 이승준;장병탁
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.04b
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    • pp.280-282
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    • 2002
  • 본 논문은 웹 문서 여과시 사용자 모델링을 위해 사용되는 연관성 피드백 방법을 강화 학습 프레임웍에서 분석하고 강화학습 기반의 새로운 연관성 피드백 알고리즘을 제안한다. 제안된 방법은 강화 학습 프레임책상에서 기존의 방법을 일반화한 것으로 기존의 연관성 피드백 방법이 현재의 프로파일만을 상태로 사용하는 데 비해 과거 history부터 얻는 추가 정보를 사용하는 방법이다

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Experimental Study on Variation of Shear Strength of Reinforced Concrete Beams According to Design Parameters (설계변수에 따른 철근콘크리트 보의 전단강도 변화에 대한 실험연구)

  • Oh, Dong-Hyun;Choi, Kyung-Kyu;Park, Hong-Gun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.11a
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    • pp.279-282
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    • 2005
  • Experimental study is performed to investigate the variation of shear strength of reinforced concrete beams according to design parameters. The major parameters are loading condition, shear span-to-depth ratio, ratio of tensile longitudinal reinforcement, prestress and boundary rigidity.14 reinforced concrete beams without web reinforcement are tested under monotonic downward loading. The shear strength of the tested specimens were compared with the prediction by design code and Choi's method.

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The Effect of Longitudinal Steel Ratio on Shear Strength of Reinforced High Strength Concrete Beams (주철근비에 따른 고강도콘크리트보의 전단강도 특성)

  • 김진근;박연동
    • Proceedings of the Korea Concrete Institute Conference
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    • 1992.04a
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    • pp.131-136
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    • 1992
  • Eight singly reinforced high strength concrete beams without web reinforcement were tested to investigate their behavior and to determine their ultimate shear capacities. In this study, the main variable was the ration of longitudinal reinforcement. Test results were compared with strength predicted by using ACI code, Zsutty's dquation and Bazant & Kim's equation. As the result, for the beams of low steel ratio, the margin of safety in ACI code may be disappeared. It was shown that Zsutty.s equation well predict the trend of the test data.

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Maximum Shear Reinforcement of RC Beams using High Strength Concrete (고강도 콘크리트를 사용한 RC보의 최대철근비)

  • Lee, Jung-Yoon;Hwang, Hyun-Bok
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.839-842
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    • 2008
  • The ACI 318-05 code requires the maximum amount of shear reinforcement in reinforced concrete (RC) beams to prevent possible sudden shear failure due to over reinforcement. The design equations of the maximum amount of shear reinforcement provided by the current four design codes, ACI 318-05, CSA-04, EC2-02, and JCI-99, differ substantially from one another. The ACI 318-05, CSA-04, and EC2-02 codes provide an expression for the maximum amount of shear reinforcement ratio as a function of the concrete compressive strength, but Japanese code does not take into account the influence of the concrete compressive strength. For high strength concrete, the maximum amount of shear reinforcement calculated by the EC2-02 and CSA-04 is much greater than that calculated by the ACI 318-05. This paper presents the effects of shear reinforcement ratio and compressive strength of concrete on the maximum shear reinforcement in reinforced concrete beams. Ten RC beams having various shear reinforcement ratio were tested. Although the test beams were designed to have much more amount of shear reinforcement than that required in the ACI 318-05 code, all beams failed due to web concrete crushing after the stirrups reached the yield strain.

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An Experimental Study of Perfobond FRP-Concrete Composite Beam (퍼포본드 FRP-콘크리트 합성보의 실험적 연구)

  • Yoo, Seung-Woon;Kook, Moo-Sung
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.2
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    • pp.121-127
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    • 2010
  • An experimental study of composite beam with perforated fiber reinforced polymer(FRP) plank as a permanent formwork and the tensile reinforcement was performed. A combined formwork and reinforcement system can facilitate rapid construction of concrete members since no conventional formwork is needed, which requires time consuming assembly and dismantling. In order for a smooth FRP plank to act compositely with the concrete, the surface of the FRP needs to be treated to increase its bond properties. Aggregates were bonded to the FRP plank using a commercially available epoxy and perforated web of plank. No additional flexural or shear reinforcement was provided in the beams. For comparison, two control specimens were tested. One control had no perforated hole in the web of FRP plank and the other had internal steel reinforcing bars instead of the FRP plank. The beams were loaded by central patch load to their ultimate capacity. This study demonstrates that the perforated FRP plank has the potential to serve as a permanent formwork and reinforcing for concrete beam.

Influence of Inclined Reinforcement around Openings on the Shear Behavior of Reinforced Concrete Continuous Deep Beams (철근콘크리트 연속 깊은 보의 전단 거동에 대한 개구부 경사 보강근의 영향)

  • Chung, Heon-Soo;Sim, Jae-Il;Yang, Keun-Hyeok
    • Journal of the Korea Concrete Institute
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    • v.19 no.2
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    • pp.171-178
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    • 2007
  • Twelve reinforced concrete continuous deep beams having web openings within interior shear spans were tested to failure. All beams tested had the same geometrical dimensions. The main variables investigated were the opening size and amount of inclined reinforcement around openings. An effective inclined reinforcement factor combining the influence of the opening size and amount of inclined reinforcement on the structural behavior of the beams tested is proposed. It was observed that the load distribution, diagonal crack width, and load capacity of beams tested were greatly dependent on the effective inclined reinforcement factor which ranged from 0 to 0.171 for the test specimens. The higher this factor, the smaller the diagonal crack width and its development rate. A higher load capacity also developed in beams having effective inclined reinforcement factor above 0.077 than in the corresponding solid deep beams. A numerical technique based on the upper bound analysis of the plasticity theory is proposed to evaluate the load capacity of continuous deep beams having openings within interior shear spans. Predictions obtained from the proposed formulas are in good agreement with test results.

Lattice Shear Reinforcement for Earthquake-Resistance of Slab-Column Connection. (슬래브-기둥 접합부의 내진성능을 위한 래티스 전단보강)

  • Kim, You-Ni;Park, Hong-Gun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05a
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    • pp.26-29
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    • 2006
  • A flat plate-column connection is susceptible to brittle punching shear failure, which may result in the necessity of shear reinforcement. In present study, experimental tests were performed to study the capacity of slab-column connections strengthened with lattice, stud rail, shear band and stirrup under gravity and cyclic lateral load. Among them, the capacity of the specimens with lattice are superior to the others due to the truss action of the lattice bars and dowel action of the longitudinal bars as well as the shear resistance of the web re-bar. On the other hand, the strengths of the specimens with stud rail, shear band and stirrup are lower than the estimated strength by the ACI, therefore design formulas of the ACI are needed to revise.

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An Analysis of Posthuman's Body Type and Fashion in SF Movies (SF 영화에 나타난 포스트휴먼의 신체 유형 및 패션 분석)

  • Choi, Jung-Hwa
    • The Research Journal of the Costume Culture
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    • v.19 no.3
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    • pp.473-487
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    • 2011
  • The purpose of this study is to analyze the body type and fashion of posthuman in SF movies. The method of this study was to analyze documentaries, internet web site, fashion books and so forth. The results were as follows: The body types of posthuman were expressed as mutation type, prosthetic type, clone type by biological hybrid or renovation and digital type by computer simulation. The mutation type was expressed as reinforcement of masculinity or feminity and reinforcement of body functions. The fashion item was expressed as a black tailored suit, leather jacket, cat suit, whip, black sunglass, garter belt, high heel shoes, short pants, black one piece dress and functional body suit. The prosthetic type was expressed as reinforcement of body functions and reinforcement of masculinity or feminity. The fashion item was expressed as a military item, high-tech power suit and ergonomic armor suit. The clone type was expressed as the plural ego with reinforcement of body functions. The fashion item was expressed as a power shoulder jacket, fake fur coat, vinyl, black see-through look and functional suit. The digital type was expressed as reinforcement of masculinity or feminity and the plural ego with reinforcement of body functions. The fashion item was expressed as a data suit, leather jacket, black over coat, boots, black sun glass, ethnic items and military items. The meanings of posthuman fashion in SF movies were impurity of posthuman, display of superhuman's power by sexuality, metaphor of power and fantasy of superhero in opposition futuristic dystopia. As mentioned above, posthuman body type and fashion in SF movies become the conversational topic in the real world. The fact that we think about utopia and identity of posthuman in the future is of great significance.

Evaluation of Structural Performance of Precast Prestressed Hollow-Core Slabs with Shear Reinforcement (전단철근이 배치된 프리캐스트 프리스트레스트 중공슬래브의 구조성능 평가)

  • Sang-Yoon Kim;Seon-Hoon Kim;Deuck-Hang Lee;Sun-Jin Han;Kil-Hee Kim
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.27 no.1
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    • pp.71-77
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    • 2023
  • This study aims to investigate the structural performance of hollow-core slab (HCS) memebers with 400 mm thickness. To this end, a total of four HCS specimens were fabricated based on the individual mold method to provide shear reinforcement, unlike the extrusion method. The key variables were chosen as the presence of topping concrete, core-filling concrete, and shear reinforcements. The crack patterns and load-displacement responses of the test specimens were analyzed in detail. Test results showed that inclined shear cracking occurred all the specimens, and that the specimen with shear reinforcement on the web of HCS unit had higher strength and ductility than the specimen without shear reinforcement. In particular, shear reinforcements placed on the web of HCS unit effectively resisted not only to vertical shear force but also to horizontal shear force between the interface of HCS unit and topping concrete. In addition, it was discovered that the method in which shear reinforcements are placed on the web of HCS unit is more effective in improving structural performance than core-filling method.

Cyclic testing of steel I-beams reinforced with GFRP

  • Egilmez, O. Ozgur;Yormaz, Doruk
    • Steel and Composite Structures
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    • v.11 no.2
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    • pp.93-114
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    • 2011
  • Flange and web local buckling in beam plastic hinge regions of steel moment frames can prevent beam-column connections from achieving adequate plastic rotations under earthquake-induced forces. This threat is especially valid for existing steel moment frame buildings with beams that lack adequate flange/web slenderness ratios. As the use of fiber reinforced polymers (FRP) have increased in strengthening and repair of steel members in recent years, using FRPs in stabilizing local instabilities have also attracted attention. Previous computational studies have shown that longitudinally oriented glass FRP (GFRP) strips may serve to moderately brace beam flanges against the occurrence of local buckling during plastic hinging. An experimental study was conducted at Izmir Institute of Technology investigating the effects of GFRP reinforcement on local buckling behavior of existing steel I-beams with flange slenderness ratios (FSR) exceeding the slenderness limits set forth in current seismic design specifications and modified by a bottom flange triangular welded haunch. Four European HE400AA steel beams with a depth/width ratio of 1.26 and FSR of 11.4 were cyclically loaded up to 4% rotation in a cantilever beam test set-up. Both bare beams and beams with GFRP sheets were tested in order to investigate the contribution of GFRP sheets in mitigating local flange buckling. Different configurations of GFRP sheets were considered. The tests have shown that GFRP reinforcement can moderately mitigate inelastic flange local buckling.